AB1665 NON-IMPAIRED KIDNEY FUNCTION INCREASES HYPERURICAEMIA-ASSOCIATED MORTALITY RISK EFFECT
Authors: J. Timsans, J. Kauppi, A. Kerola, T. Lehto, H. Kautiainen, M. Kauppi
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Both hyperuricaemia and reduced kidney function are known mortality risk factors.<sup>[1-3]</sup> Also, hyperfiltration is associated with elevated mortality risk.<sup>[3]</sup> It has not yet been studied if renal function has a modifying effect on hyperuricaemia-associated mortality risk. <h3>Objectives</h3> To detect if renal function has a modifying effect on hyperuricaemia-associated mortality risk. <h3>Methods</h3> Data from GOAL (Good Ageing in Lahti region) study was used. It is a large, prospective, population-based study of elderly people (52–76 years) in the Lahti region. Data of serum uric acid (SUA) levels, creatinine, cystatin C as well as several other laboratory variables, comorbidities, lifestyle habits and socioeconomic factors was collected. To estimate glomerular filtration rate, we used CKD-EPI creatinine-cystatin C equation (ml/min/1.73 m<sup>2</sup>). Persons with SUA values of &gt;410 μmol/L (75<sup>th</sup> percentile) are represented as clearly hyperuricaemic. Persons with eGFR of ≤67 ml/min (25<sup>th</sup> percentile) are represented as having reduced kidney function. The results were adjusted for age, gender, education, smoking status, alcohol consumption, body mass index, hypertension and dyslipidaemia. <h3>Results</h3> Mortality was higher in individuals with reduced kidney function compared to those with eGFR of &gt;67 ml/min both in the group of clearly hyperuricaemic persons and in the group of persons with SUA ≤410 μmol/L. The hazard ratio (HR) for all-cause mortality was 1.53 (95% CI: 1.26 to 1.84) in clearly hyperuricaemic persons with reduced kidney function, 1.26 (95% CI: 1.02 to 1.55) in clearly hyperuricaemic persons with eGFR of &gt;67 ml/min, 1.26 (95% CI: 1.03 to 1.55) in persons with SUA ≤410 μmol/L and reduced kidney function, while the group of SUA ≤410 μmol/L and eGFR &gt;67 ml/min was used as a reference (Table 1). HR for hyperuricaemia-related premature death however was lowest in individuals with reduced eGFR, and it rises strikingly as the eGFR increases above 80ml/min (Figure 1). <h3>Conclusion</h3> Reduced kidney function is an important risk factor for mortality both in individuals with lower and higher SUA. The mortality risk associated with hyperuricaemia is remarkably higher in individuals with normal or only slightly reduced kidney function. This finding makes it reasonable to speculate that hyperuricaemia caused by overproduction of uric acid (metabolic hyperuricaemia) might be a separate and more deleterious entity than hyperuricaemia that has resulted from renal underexcretion of uric acid (renal hyperuricaemia). <h3>References</h3> [1]Konta T, et al. <i>Sci Rep</i>. 2020;10(1):6066 [2]Juraschek SP, et al. <i>Atherosclerosis</i>. 2014;233(2):623-629 [3]Korhonen PE, et al. <i>J Gen Intern Med</i>. 2022;10.1007/s11606-022-07885-8. <h3>Acknowledgements</h3> We thank all the participants in the GOAL (Good Ageing in Lahti region) project. <h3>Disclosure of Interests</h3> None Declared.